Use grub theme repo

Author: jackpot51

.gitmodules

@@ -1,4 +1,3 @@
-[submodule "data/default-settings"]
-	path = data/default-settings
-	url = https://github.com/system76/pop-default-settings.git
-	branch = master
+[submodule "data/grub-theme"]
+	path = data/grub-theme
+	url = https://github.com/system76/pop-grub-theme.git

data/default-settings

@@ -135,7 +135,7 @@ $(BUILD)/iso_data.tag: $(BUILD)/iso_create.tag $(BUILD)/grub
 	cp "/usr/lib/grub/x86_64-efi/"* "$(BUILD)/iso/boot/grub/x86_64-efi/"
 
 	# Copy grub theme
-	cp -r "data/default-settings/usr/share/grub/themes" "$(BUILD)/iso/boot/grub/themes"
+	cp -r "data/grub-theme/usr/share/grub/themes" "$(BUILD)/iso/boot/grub/themes"
 
 	touch "$@"